Early Timing Cover Screws E.6980 & 24689

robs ss · Dec 5, 2016

Sorry to re-awaken this thread but I have a question.....
It appears that timing cover screws on dominators (vertical twins 1947-1971??) had a specified fibre washer (#20621A - 12 off) for the timing cover. Does anyone use these? Are they of any value? Are they better eliminated?
Any advice welcome
Cheers
Rob

jimbo · Dec 5, 2016

robs ss said:
Sorry to re-awaken this thread but I have a question.....
It appears that timing cover screws on dominators (vertical twins 1947-1971??) had a specified fibre washer (#20621A - 12 off) for the timing cover. Does anyone use these? Are they of any value? Are they better eliminated?
Any advice welcome
Cheers
Rob

I did not know Nortons had the head washers, Royal Enfield's did, and you can get the fiber ones here.

http://www.hitchcocksmotorcycles.com/pa ... r_Assembly

jimbo · Dec 5, 2016

https://andover-norton.co.uk/en/shop-drawing/451/engine

N0rt0nelectr@ · Dec 5, 2016

jimbo said:
robs ss said:

Sorry to re-awaken this thread but I have a question.....
It appears that timing cover screws on dominators (vertical twins 1947-1971??) had a specified fibre washer (#20621A - 12 off) for the timing cover. Does anyone use these? Are they of any value? Are they better eliminated?
Any advice welcome
Cheers
Rob

Click to expand...

I did not know Nortons had the head washers, Royal Enfield's did, and you can get the fiber ones here.

http://www.hitchcocksmotorcycles.com/pa ... r_Assembly

I remember getting a gasket set from my old Norton / Matchless dealer back in the 70's that came with the fiber gaskets. I never used them myself.
John in Texas

jimbo · Dec 5, 2016

N0rt0nelectr@ said:
jimbo said:

robs ss said:

Sorry to re-awaken this thread but I have a question.....
It appears that timing cover screws on dominators (vertical twins 1947-1971??) had a specified fibre washer (#20621A - 12 off) for the timing cover. Does anyone use these? Are they of any value? Are they better eliminated?
Any advice welcome
Cheers
Rob

Click to expand...

I did not know Nortons had the head washers, Royal Enfield's did, and you can get the fiber ones here.

http://www.hitchcocksmotorcycles.com/pa ... r_Assembly

Click to expand...

I remember getting a gasket set from my old Norton / Matchless dealer back in the 70's that came with the fiber gaskets. I never used them myself.
John in Texas

Actually the RE's had tiny thin metal ones originally, the suppliers only sell fiber ones now :shock:

Matchless · Dec 5, 2016

Just for the record my 1962 650ss has had aluminium washers under the T.C screws from new.

Martyn.

robs ss · Dec 6, 2016

Jimbo
I think your link from AN shows no washers for timing cover screws therefore not needed.
I have found, as you may also have, that not all parts are shown in exploded diagrams.
The three shots below show the washers, although not shown on the diagram are called up in the list (20621A - 12 off, just below item 112)

Martyn - I like the idea of aluminium washers but can't find any. Custom Fasteners (Wales) have copper washers that would appear to fit - may try them - still trying to work out if anything here is needed.
Cheers
Rob

Early Timing Cover Screws E.6980 & 24689

Matchless · Dec 8, 2016

What is listed in the parts book isn't necessarily what was fitted. The twin engine exploded diagram in the 1961 parts book is of a pre 1959 engine (different shape head & barrel). Hence my aluminium washers. As I mentioned in a previous thread,the steering head bearings on my bike from new were the angular contact type, not the usual cup & loose ball type. I think British factories often fitted what was available at the time.

Rohan · Dec 8, 2016

Matchless said:
As I mentioned in a previous thread,the steering head bearings on my bike from new were the angular contact type, not the usual cup & loose ball type. I think British factories often fitted what was available at the time.

Unless you bought this bike from new, isn't it more likely that a PO replaced the steering bearings at some time.?!
They get a tough life, and are considered to be consumables.

And if Nortons did this from new, they'd get a mention in the parts books.
And if Nortons did this from new, other owners would have noted their fitment also...

Matchless · Dec 8, 2016

Rohan,

I acquired my 650 from the first owner. He bought the bike brand new in February 1962 & covered just over 11,000 miles on it before it threw a rod. It then spent almost forty years at the back of his garage. When I bought it, the only non original parts were a pair of long megas he had fitted for a bit more volume, & the rear tyre. Even all the rubber parts including the front tyre, were as fitted when it left Bracebridge street.
If you can wear out a set of head bearings before a front tyre, you're a better man than me Gunga Din.

Martyn.

Rohan · Dec 8, 2016

If they are not correctly adjusted, they will wear out in no time. !

Rohan · Dec 8, 2016

Heck, if they are not regularly lubed, they can develop rust patches.
As me how I know this...

And unless you specifically asked him if he'd changed them,
we may be jumping to some rather hasty conclusions here....
By and large, if they are shown not in the Parts Book, then they are something the PO has done. (?)

If we can get some reports from other owners - with exactly the same bearings installed - it may be another matter. Care to name the actual bearings you found ?

Matchless · Dec 9, 2016

The parts book for 1961 lists frame headlug bearing part number 18263 2 off. All later parts books list bearing race 030097 2 off, ball bearings 000021 36 off. I will have a rumage through a few boxes of old junk & see if I can find the old bearings, but they more than likely went in the scrap bin ten years ago.

Early Timing Cover Screws E.6980 & 24689

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